The following description relates to actuators and, more specifically, to cooling flow limiters of gas turbine engine actuators.
Gas turbine engine actuators often operate in hot environments and thus can be subject to high temperature and fire resistance requirements that need to be met. A typical mitigation solution for complying with such requirements is with a provision for quiescent cooling flow to a slave actuator (i.e., an actuator with an electro-hydraulic servo valve (EHSV) controller located remotely from the actuator) but doing so can be challenging. This is due to the fact that because a pressure differential that is available to drive the cooling flow is the differential between extend and retract pressures and, depending on actuator loads, this differential can vary by a large amount. A cooling flow orifice must therefore be sized for the lowest expected or actual pressure differential that may be experienced and as a result tends to permit excess cooling flow at higher differentials. This results in a parasitic flow loss and system heating.